Holding breath in Second trimester

I feel like I have hurt my baby girl. I have done this quite a few times not thinking anything of it when passing certain smells. I held it for multiple times 30-40s to get past a smell. One time for even a minute because I was trapped in the car. I’m so worried I cause her brain damage from lack of oxygen from my blood. Please be kind because I’m just trying to protect my baby and I feel like I’m failing her already. I’m feel like I’m going to be a horrible mom since I can’t even get this right.